If We Model After-Tax Household Income with a Normal Distribution

Multiple Choice

If we model after-tax household income with a normal distribution, then the figures of a 1995 study imply the information in the following table. Assume that the distribution of incomes in each country is normal, and round all percentages to the nearest whole number. What percentage of Swedish households are either very wealthy (income at least $100,000) or very poor (income at most $12,000) Express your answer to the nearest 1%. $$\begin{array} { | l | l | l | l | l | l | } \hline \text { Country } & \text { U.S. } & \text { Canada } & \text { Switzerland } & \text { Germany } & \text { Sweden } \\\hline \begin{array} { l } \text { Mean } \\\text { household } \\\text { income }\end{array} & \$ 38,000 & \$ 35,000 & \$ 39,000 & \$ 34,000 & \$ 32,000 \\\hline \begin{array} { l } \text { Standard } \\\text { deviation }\end{array} & \$ 21,000 & \$ 17,000 & \$ 16,000 & \$ 14,000 & \$ 11,000 \\\hline\end{array}$$

A) 51%
B) 3%
C) 7%
D) 6%
E) 97%